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// SPDX-License-Identifier: GPL-2.0-only
/* Some common code for MSG_ZEROCOPY logic
*
* Copyright (C) 2023 SberDevices.
*
* Author: Arseniy Krasnov <avkrasnov@salutedevices.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/errqueue.h>
#include "msg_zerocopy_common.h"
void vsock_recv_completion(int fd, const bool *zerocopied)
{
struct sock_extended_err *serr;
struct msghdr msg = { 0 };
char cmsg_data[128];
struct cmsghdr *cm;
ssize_t res;
msg.msg_control = cmsg_data;
msg.msg_controllen = sizeof(cmsg_data);
res = recvmsg(fd, &msg, MSG_ERRQUEUE);
if (res) {
fprintf(stderr, "failed to read error queue: %zi\n", res);
exit(EXIT_FAILURE);
}
cm = CMSG_FIRSTHDR(&msg);
if (!cm) {
fprintf(stderr, "cmsg: no cmsg\n");
exit(EXIT_FAILURE);
}
if (cm->cmsg_level != SOL_VSOCK) {
fprintf(stderr, "cmsg: unexpected 'cmsg_level'\n");
exit(EXIT_FAILURE);
}
if (cm->cmsg_type != VSOCK_RECVERR) {
fprintf(stderr, "cmsg: unexpected 'cmsg_type'\n");
exit(EXIT_FAILURE);
}
serr = (void *)CMSG_DATA(cm);
if (serr->ee_origin != SO_EE_ORIGIN_ZEROCOPY) {
fprintf(stderr, "serr: wrong origin: %u\n", serr->ee_origin);
exit(EXIT_FAILURE);
}
if (serr->ee_errno) {
fprintf(stderr, "serr: wrong error code: %u\n", serr->ee_errno);
exit(EXIT_FAILURE);
}
/* This flag is used for tests, to check that transmission was
* performed as expected: zerocopy or fallback to copy. If NULL
* - don't care.
*/
if (!zerocopied)
return;
if (*zerocopied && (serr->ee_code & SO_EE_CODE_ZEROCOPY_COPIED)) {
fprintf(stderr, "serr: was copy instead of zerocopy\n");
exit(EXIT_FAILURE);
}
if (!*zerocopied && !(serr->ee_code & SO_EE_CODE_ZEROCOPY_COPIED)) {
fprintf(stderr, "serr: was zerocopy instead of copy\n");
exit(EXIT_FAILURE);
}
}
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